Orbital sign up ATK for solid partnership with Stratolaunch ALV

August 13, 2013 by Chris Bergin

ATK are now officially on board with the Stratolaunch system, following a deal with the launch vehicle’s main partner, Orbital Sciences Corporation. ATK will provide the first and second stages for the vehicle – nicknamed Pegasus II – that will be air-launched from a huge carrier plane, with test flights set to begin as early as 2017.

Stratolaunch:

Announced at the end of 2011, Stratolaunch was revealed as a collaboration between inventor, investor and philanthropist Paul G. Allen and Scaled Composites founder Burt Rutan.

While the SLF’s 300 feet wide, 15,000 feet long strip, is firmly in Stratolaunch’s sights as the potential East Coast location for their missions, the focus will initially be to the west, with Stratolaunch systems already signed up to a 20-year lease agreement with the Kern County Airport Authority, Mojave, California, for the lease of 20 acres at the Mojave Air and Space Port.

These two stages will sport additional performance via an updated propellant mix, under development by ATK, who officially joined the team via a statement on Tuesday.

“ATK is pleased to receive this award for the development and production of first and second stage propulsion for the Stratolaunch ALV,” said Blake Larson, president of ATK Aerospace Group. “Our innovative propulsion concept combines both proven and state-of-the-art technologies that will provide a high-performing, cost-effective solution for the ALV.”

The contract from Orbital includes the design, development and flight hardware for initial Stratolaunch missions and expands on their partnership that dates back to the development of Orbital’s original air-launched vehicle, Pegasus, which also uses ATK solid rocket motors for stage propulsion.

“Our design solution for the ALV will take full advantage of ATK’s experience with large diameter solid rocket motors, like those built for the Space Shuttle and for the Titan IVB launch vehicle,” added Scott Lehr, vice president and general manager of ATK’s Defense and Commercial Division.

“Solid rocket motors use stable propellants and have proven highly reliable in a wide variety of systems. They are highly engineered systems that are designed for simplified operations, and minimize ground support infrastructure requirements.”

Per the additional details provided to L2, the rocket will also have a Thrust Vector Control (TVC) system on both the first and second stages – unlike Pegasus, which does not have a TVC on its first stage.

The first two stages will act like a single first stage, given they will provide half of the required Delta-v. However, new information notes the first stage may also be recoverable after staging and splashdown.

Once the solid stages have been expended, a restartable cryogenic third stage – currently baselined as utilizing two Pratt & Whitney Rocketdyne (PWR) RL-10 engines for the development and early flights of the rocket – will be used, pending development of a higher thrust LOX-Hydrogen unit.